Radiation fetal

The exact fetal radiation dose must be calculated for every case of exposure, based on information on file at each hospital. As a rule of thumb, until accurate dose calculations can be performed, you may make the following assumptions ... 

One CT that images the uterus will give a fetal radiation dose of 2 to 5 rem. 

In September 1998,1 received a call from Radiology saying that a woman had been involved in an automobile accident. Arriving unconscious, she received several X-rays and a CT scan of the abdomen and pelvis. When she awoke, she informed the physicians she was pregnant. I was asked to calculate the fetal radiation dose. 

Several times each year, I receive phone calls or e-mail from women who have been advised to terminate their pregnancy after receiving only a few X-rays, some of which do not even image the uterus. Many medical personnel continue to fear that all fetal radiation exposure is harmful, and they inappropriately recommend therapeutic abortion. Before making this recommendation, medical personnel must perform a fetal dose calculation or ask a knowledgeable medical physicist or health physicist to perform these calculations. No recommendation to terminate a pregnancy should be made until these calculations have been performed and evaluated by a competent medical physicist or health physicist. 

Protection and Measnrements (NCRP) Report Nnmber 28, Radionuclide Exposure of the Embryo/Fetus contains information useful for estimating fetal exposures. The report, available at http //www.ncrponline.org/ncrprpts.html (last accessed 1-29-06) contains fetal radiation dose estimates for 83 radionuclides (14). The report also contains information the mechanisms and consequences of prenatal radiation exposure. 

Hibbard BM, Herbert RJT (1960) Fetal radiation dose following administration of radio-iodinated albumin. Clin Sci 19 337-344... 

Moskalev JI, Buldakov LA, Lyaginskaya AM, et al. 1969. Experimental study of radionuclide transfer through the placenta and their biological action on the fetus. In Radiation biology of the fetal and juvenile Mmmmal Richland, WA Hanford Biology Symposium, 153-160. 

Matsusaka, N. J., Inaba, R., Ichikawa, M., Ikeda, M. and Oikubo, Y. (1969). Some special features of nuclide metabolism in juvenile mammals, page 217 in Radiation Biology of the Fetal and Juvenile Mammal, AEC Symposium Series No. 17, Report No. CONF-690501 (National Technical Information Service, Springfield, Virginia). 

Norton, S. and B.F. Kinder. 1990. Early effects of low doses of ionizing radiation on the fetal cerebral cortex in rats. Radiation Res. 124 235-241. 

It has been demonstrated that At is embryotoxic in pregnant mice, and there also exists a dose-related occurrence of associated fetal malformations (29, 30). Long-term studies in female rats that had received 0.5 /tCi g At systemically indicated a significant incidence of radiation-induced mammary carcinomata (39/45 44%) and endometrial polyps (43/55 76.4%) at 14 months after treatment. No thyroid tumors were found (50). Detailed macroscopic radiation dosimetric studies related to the biodistribution of At in animal models have been reported (29, 33, 39). 

Children Coeur d Alene, Silver Valley, ID Solar radiation (ultraviolet light) Arsenic Estimated number of children with fetal alcohol syndrome. Town contaminated by lead. Sunburn, cancer. Found in drinking water, and old smelter and mining sites, causes skin disease and cancer. 

GH deficiency can have a genetic basis or can be acquired as a result of damage to the pituitary or hypothalamus by a tumor, infection, surgery, or radiation therapy. In childhood, GH deficiency presents as short stature and adiposity. (Neonates with isolated GH deficiency are of normal size at birth, presumably because fetal GH is not required for normal... 

My calculations showed a fetal dose of just less than 5 rad, which I reported to the attending physician and the woman s OB/GYN. I also reported that, for this level of exposure, the medical recommendation was to allow the pregnancy to proceed without consideration of the radiation exposure. This advice was followed and the pregnancy ended happily. 

Fetal problems, including abortion, stillbirths, congenital anomalies, neurological cretinism. Goiter, hypothyroidism, impaired mental function, increased susceptibility to radiation. 

This text contains a series of reviews on the toxic effects of drugs and other compounds, viruses, radiation, and occupational hazards. A chapter on drugs of choice in pregnancy and a section on diagnosis of fetal malformations are included. An online version is available. 

Approximately 7% of all live-born humans bear birth defects. This value may be as high as 10% if children are evaluated to age 10 years to include subtle structural or functional deficits such as minimal brain dysfunction or attention deficit disorders. More than 560 000 lives out of 3 million births per year in the United States are lost through infant death, spontaneous abortion, stillbirths, and miscarriage due presumably to defective fetal development. The relative contributions to human teratogenesis have been estimated as follows known germinal mutations, 20% chromosomal and gene aberrations, 3-5% environmental causes such as radiation, <1% infections, 2% or 3% maternal metabolic imbalance, 1% or 2% drugs and environmental chemicals, 4% or 5% contributions from maternal dietary deficiencies or excesses and... 

Hyperthermia induced by an elevation in ambient temperature following RF radiation is known to be associated with fetal developmental effects. 2-Methoxyethanol is a known teratogen. In a study on laboratory animals it was demonstrated that combined exposure to RF and 2-methoxyethanol enhanced the adverse effects produced by either agent alone. It was also noted that teratogenic effects of 2-methoxyethanol were observed at levels below those found for the solvent alone, when it was co-administered with RFJ251... 

Depending on the dose, dose rate and route of exposure, radiation can cause Acute Radiation Syndrome (ARS), cutaneous injury and scarring, chorioretinal damage (due to exposure to infrared energy), and increased long term risk for cancer, cataract formation (especially due to neutron irradiation), infertility and fetal abnormalities, such as growth retardation, fetal malformations, increased teratogen-esis and fetal death (2). 

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